The present invention relates to an improved pressure balance valve for use in a pipeline of a common cold and hot water faucet, which is designed to prevent people from being scalded by excessively hot water in use. It has a sleeve and a pressure balance valve that are integrally assembled together so that they can be dismantled as one easily for cleansing purpose. The sleeve and balance valve are designed in such a way that water flows therethrough in a smoother and more direct manner.
In general, a conventional pressure balance valve, as shown in FIG. 1, is comprised of a valve embodiment 10, a sleeve 20, a balance valve 30, a pair of rubber stoppers 40 and a sealing cap 50. The valve embodiment 10 is of an H-shaped form having a cold water inlet 11 at the top of the right portion of the valve embodiment 10 and a hot water inlet 12 at the top of the left portion thereof. A balance valve chamber 13 is horizontally disposed at the central portion thereof. Next to the right end of the balance valve chamber 13 is disposed an enlarged cold water inlet space 131 in communication with the cold water inlet 11. Next to the left end of the balance valve chamber 13 is disposed a hot water inlet space 132 communicating with the hot water inlet 12. To the right of the middle of the balance valve chamber 13 is defined a cold water outlet space 133 which communicates with an internally threaded cold water outlet 14 disposed at the bottom of the outlet space 133. A hot water outlet space 134 is placed to the left of the middle of balance valve chamber 13 with an internally threaded hot water outlet 15 communicating with the bottom thereof. To the right side of the valve embodiment 10 is disposed an internally threaded opening 16 in communication with the balance valve chamber 13.
The sleeve 20 is a hollow tube on the right portion of which are disposed 2 rings of 4 spaced cold water inlet holes 21 and cold water outlet holes 23 respectively. On the left portion of the sleeve are identically disposed 2 rings of 4 spaced hot water inlet holes 22 and hot water outlet holes 24 respectively. The tubular balance valve 30 is divided into a cold water space 31 and a hot water space 32. At the end of the cold water space 31 and hot water space 32 is disposed a flanged countersunk cavity 311, 321 respectively. The balance valve 30 is divided into a cold water section 33 and a hot water section 34 with a partition board 35 disposed therebetween. A groove 351 is disposed on the periphery of the partition board 35 for the location of a sealing ring. On the cold water section 33 and hot water section 34 are disposed respectively a pair of symmetric cold water passage holes 331 and hot water passage holes 341. The rubber stopper 40 has a hollow interior and the sealing cap 50 has a hexagonal driving section 50 and an externally threaded stem 52 having a bottom cavity 53.
As shown in FIG. 2, the sectional diagram shows the assembly of the prior art balance valve of FIG. 1. First, the rubber stoppers 40 are stuffed into the countersunk cavities 311, 321 of the balance valve 30 respectively and then the balance valve 30 is placed in the hollow interior of the sleeve 20 which is then inserted into the balance valve chamber 13 of the valve embodiment 10 via the opening 16. The cold water inlet holes 21 and hot water inlet holes 22 are placed in the cold water inlet space 131 and hot water inlet space 132 respectively. The cold water outlet holes 23 and hot water outlet holes 24 are placed in the cold water outlet space 133 and hot water outlet space 134 respectively. At last the sleeve 20 is placed via the opening 16 and locked inside the valve chamber 13 of the valve embodiment 10 by the sealing cap 50. In use, the cold water inlet 11 and hot water inlet 12 are connected to a cold water source by a supplying pipe 1 and to a heater by a hot water supplying pipe 2. The cold water outlet 14 and hot water outlet 15 are connected to a faucet by way of a cold water discharge pipe 3 and a hot water discharge pipe 4 respectively.
Referring to FIG. 3, the operation mode of the pressure balance in the prior art balance valve is illustrated. Cold water is first led from a water source by the cold water supplying pipe 1 into the valve embodiment 10 via the cold water inlet 11. Then the cold water passes sequentially the cold water inlet space 131, the cold water inlet holes 21 of the sleeve 20, the cold water section 33 of the balance valve 30, the cold water outlet holes 23 of the sleeve 20, the cold water outlet space 133 of the valve embodiment 30, the cold water outlet 14 and it is finally discharged out of a faucet via the cold water discharge pipe 3.
Similarly, the hot water is first led from a water source by the hot water supplying pipe 2 into the valve embodiment 10 via the hot water inlet 12. Then the hot water passes sequentially the hot water inlet space 132, the hot water inlet holes 22 of the sleeve 20, the hot water section 34 of the balance valve 30, the hot water outlet holes 24 of the sleeve 20, the hot water outlet space 134 of the valve embodiment 30, the hot water outlet 15 and it is finally discharged out of a faucet via the hot water discharge pipe 4.
As the pressure of the in-flow cold water is suddenly dropped, part of the hot water will push one side of the partition board 35 of the hot water section 34 of the balance valve 30 and the side wall of the flanged countersunk cavity 321. And the other part of the hot water will flow in through the hot water inner passage hole 341 of the valve 30, and passes through the hot water space 32, the hollow interior of the rubber stopper 40 and pushes in a hot water side sliding room the balance valve 30 toward the cold water side with the cold water in the cold water sliding room squeezed to dispense slowly. It will further block hot water from entering via the hot water inlet holes 22 of the sleeve 20.
Such a prior art pressure balance valve has the following disadvantages in practical use:
1. The sleeve 20 is stuffed into the valve chamber 13 via the opening 16 of the valve embodiment 10 and the sealing cap 50 is engaged with the opening 16. If one wants to cleanse the sleeve 20 and the balance valve 30, it is relatively hard to get them out, causing inconvenience in use. PA0 2. The outer surface of the sleeve 20 is smooth and not provided with ring grooves 351 to locate sealing rings. The sleeve 20 is placed directly inside the valve chamber 13, causing cold water and hot water to mix via penetration. The temperature of water is not precisely controlled. PA0 3. The balance valve 30 housed in the sleeve 20 produces sliding room which will become a half vacuum state when water flows into the valve 30. As balance of pressures between cold and hot water is lost, the valve 30 can not be responsive instantly, causing hot water to flow out excessively. PA0 4. Debris will be easily accumulated in the sliding room at both ends of the sleeve 20 as the balance valve 30 is placed therein as a result of water not flowing directly in the room.
Thus the movement of the valve 30 will be negatively influenced in long period, making the scald-proof feature of the valve less effective.